title: Multiple activities of insect repellents on odorant receptors in mosquitoes.
abstract: Several lines of evidence suggest that insect repellent molecules reduce mosquito-host contacts by interacting with odorants and odorant receptors (ORs), thereby ultimately affecting olfactory-driven behaviours. We describe the molecular effects of 10 insect repellents and a pyrethroid insecticide with known repellent activity on two highly specific Aedes aegypti (Diptera: Culicidae) ORs, AaOR2 + AaOR7 and AaOR8 + AaOR7, exquisitely sensitive to key mosquito attractants indole and (R)-(-)-1-octen-3-ol, expressed in oocytes of Xenopus (Anura: Pipidae). Our study demonstrates that insect repellents can both inhibit odorant-evoked currents mediated by ORs and independently elicit currents in the absence of odorants. All of the repellents had effects on one or both ORs; most of these compounds were selective inhibitors and showed a high degree of specificity in their capacity to activate the two ORs. These results show that a range of insect repellents belonging to structurally diverse chemical classes modulate the function of mosquito ORs through multiple molecular mechanisms.
authors.affiliation: Invasive Insect Biocontrol and Behavior Laboratory, Plant Sciences Institute, U.S. Department of Agriculture-Agricultural Research Service (USDA-ARS), Henry A. Wallace Beltsville Agricultural Research Center, Beltsville, MD, U.S.A. joseph.dickens@ars.usda.gov
authors.forename: J D
authors.initials: JD
authors.lastname: Bohbot
authors.forename: L
authors.initials: L
authors.lastname: Fu
authors.forename: T C
authors.initials: TC
authors.lastname: LE
authors.forename: K R
authors.initials: KR
authors.lastname: Chauhan
authors.forename: C L
authors.initials: CL
authors.lastname: Cantrell
authors.forename: J C
authors.initials: JC
authors.lastname: Dickens
mesh_terms: D000330:Aedes / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D005071:Evoked Potentials; D005260:Female; D007211:Indoles / Q000378:metabolism*; D007302:Insect Repellents / Q000494:pharmacology*; D000442:Octanols / Q000378:metabolism*; D009865:Oocytes / Q000187:drug effects; D010675:Pheromones / Q000378:metabolism*; D018035:Receptors, Odorant / Q000819:agonists / Q000378:metabolism*; D012903:Smell; D014982:Xenopus laevis / Q000378:metabolism
chemical_list: D007211:Indoles; D007302:Insect Repellents; D000442:Octanols; D010675:Pheromones; D018035:Receptors, Odorant; C010411:insect attractants; C030374:indole; C038844:1-octen-3-ol